>>> s = 'spam'
>>> t = list(s)
>>> print(t)
['s', 'p', 'a', 'm']

>>> s = 'pining for the fjords'
>>> t = s.split()
>>> print(t)
['pining', 'for', 'the', 'fjords']
>>> print(t[2])
the
>>> print(' '.join(t))
pining for the fjords

>>> t = ['pining', 'for', 'the', 'fjords']
>>> delimiter = ' '
>>> delimiter.join(t)
'pining for the fjords'

>>> s = 'spam-spam-spam'
>>> delimiter = '-'
>>> s.split(delimiter)
['spam', 'spam', 'spam']

🦔 Parsing lines

Usually when we are reading a file we want to do something to the lines other than just printing the whole line. Often we want to find the "interesting lines" and then parse the line to find some interesting part of the line. What if we wanted to print out the day of the week from those lines that start with "From "? From [email protected]SatJan 5 09:14:16 2008 The split method is very effective when faced with this kind of problem. We can write a small program that looks for lines where the line starts with "From ", split those lines, and then print out the third word in the line:

fhand = open('mbox-short.txt')
for line in fhand:
    line = line.rstrip()
    if not line.startswith('From '): continue
    words = line.split()
    print(words[2])